1. Field of the Invention
The present invention relates to a process for producing 1-phthalazinone and its derivatives, more particularly, to a process for producing 1-phthalazinone and its derivatives by the reaction of a benzoic acid derivative with hydrazine or a derivative thereof.
2. Description of the Prior Art
1-PHTHALAZINONE AND ITS DERIVATIVES HAVE BEEN PREPARED BY THE REACTION OF O-FORMYLBENZOIC ACID, WHICH IS DERIVED FROM PHTHALIC ANHYDRIDE VIA SEVERAL REACTION STEPS, WITH HYDRAZINE OR A DERIVATIVE THEREOF AS DESCRIBED IN P.R. Austin, E.W. Bousquet and W.A. Lazier, J. Am. Chem. Soc., 59, 864 (1937): R.L. Shriner and F.J. Wolff, Org. Synth., 23, 74 (1943); and C. Liebermann and A. Bistrzycki, Ber. Deut. Chem. Ges., 26, 531 (1893). This method of preparation, however, is disadvantageous in cost due to the multiplicity of reaction steps and the limited industrial uses of o-formylbenzoic acid.
1-PHTHALAZINONE AND ITS DERIVATIVES HAVE ALSO BEEN PREPARED FROM NAPHTHALENE, WHICH IS A LESS EXPENSIVE STARTING MATERIAL, VIA AN OXIDATION USING POTASSIUM PERMANGANATE. In this method, however, there is used an aqueous alkaline solution of potassium permanganate, the use of which involves the possibility of environmental pollution and hence requires the use of apparatus equipped to reduce discharged pollutants, which results in the use of intricate apparatus and production procedures.
Of 1-phthalazinone derivatives, those having substituent groups on the benzene ring have been prepared by other complicated processes since they are incapable of being prepared by the above processes.